Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
241–250 of 423 · Normal
Question 241
2 marks · Normal
Answer and see the solution →What is the name and symbol for the negatively charged ion formed when oxygen gains electrons?
Question 242
4 marks · Normal
Answer and see the solution →This question is about the bonding in magnesium oxide.
(a)[2 marks]Complete the dot-and-cross diagram for the oxide ion (O^{2-}) formed from an oxygen atom during the bonding in MgO. Show the arrangement of electrons in its outer shell after the transfer.
(b)[2 marks]Explain why the oxide ion has a 2- charge after bonding occurs.
Question 243
2 marks · Normal
Answer and see the solution →Describe what happens to a magnesium atom when it forms an ion. Give the charge on the ion and explain your answer.
Question 244
4 marks · Normal
Answer and see the solution →Aluminium and sulphur can both form ions.
(a)[1 mark]State the charge on the ion formed by aluminium.
(b)[1 mark]State the charge on the ion formed by sulphur.
(c)[2 marks]Explain how each atom forms its ion. Your answer should refer to the gain or loss of electrons.
Question 245
3 marks · Normal
Answer and see the solution →An atom of potassium (K, atomic number 19) forms an ion.
Calculate:
(a)[1 mark]The number of electrons in a potassium atom before ion formation.
(b)[1 mark]The number of electrons in the potassium ion after it has formed.
(c)[1 mark]The electronic configuration of the potassium ion.
Question 246
3 marks · Normal
Answer and see the solution →Phosphorus (P) forms an ion with the same number of electrons as argon (Ar).
Explain how this is possible. In your answer, include:
(a)[1 mark]The change in electron number
(b)[1 mark]The charge on the ion
(c)[1 mark]A reason why phosphorus forms this ion
Question 247
4 marks · Normal
Answer and see the solution →The table shows information about four elements and their ions.
Element Group Atomic number Ion formed Number of electrons in ion Calcium 2 20 Ca2+ Chlorine 7 17 Cl– Potassium 1 19 K+ Oxygen 6 8 O2– (a)[2 marks]Complete the column for 'Number of electrons in ion' in the table above.
(b)[2 marks]Which two ions in the table are isoelectronic with argon? Give a reason for your answer.
Question 248
1 mark · Normal
Answer and check →Which of the following ions has the same number of electrons as a neon atom?
- A.Na+
- B.Mg2+
- C.F–
- D.All of the above
Question 249
2 marks · Normal
Answer and see the solution →State the type of ion formed by barium (Ba) and how it achieves a noble gas electron configuration.
Question 250
4 marks · Normal
Answer and see the solution →Iodine (I) is in Group 7 of the periodic table.
(a)[1 mark]How many electrons does an iodine atom gain or lose to form an ion?
(b)[1 mark]What is the charge on an iodide ion?
(c)[1 mark]Write the electron configuration of the iodide ion.
(d)[1 mark]Name the noble gas that has the same number of electrons as the iodide ion.